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What is a relay switch?
An overload relay, also referred to as a relay switch, is a device that opens the circuit in the event of an electrical, thermal or power overload. When mounted with a contactor they create a motor starter. Overload relays are normally closed, meaning they only open if they experience an overload. They are used to protect motors from damage in a number of applications across industrial and commercial sectors, among others. They are available in a number of current ratings which can be adjustable on some models.
Common types of overload relays.
Overload relays are typically one of two types: thermal relays or electrical relays. The overload mechanism inside thermal relays consists of a bimetallic strip in conjunction with a heating element. When the heating element experiences an excessive current, the bimetallic strip bends and opens the normally closed contact, thus interrupting the circuit. These have adjustable current ratings to meet a variety of application requirements. On the other hand, electronic relays rely on electrical components which measure the current flowing through. While these are more accurate and are available across more current ratings, thermal relays can be more cost-effective.
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Looking to buy a new relay switch? Look no further than Bay Power. We proudly stock an extensive variety of electronic motor protection relays from leading relay manufacturers. Take your pick from ABB motor protection relays, Crydom solid state relays, GE motor protection relays, Pilz safety relays, Thermistor protective relays, Allen Bradley protective relays and more. So whether you’re looking for a thermal relay, a solid state relay, a low voltage relay switch or a high voltage relay switch, you can always count on Bay Power to provide you with the overload relay you need, always with a one-year replacement warranty.
Motor Overload Relays
Motor overload relays are designed specifically to handle all types of overloads in AC and DC motors and protect motors from potential damage. Available as either an IEC relay or a NEMA relay, motor overload relays can be used for a number of applications and can be either electronic or thermal.
Solid State Overload Relays
Solid state relays are a type of electronic relay that has no moving parts. They utilize transistors and sensors among other electronic components in order to detect an overload. They are preferable due their accuracy and their fast switching speed, as well as their applicability in low voltage and low current applications.
Thermal Overload Relays
Thermal overload relays rely on a bimetallic strip and a heating element in order to detect an overload and prevent the motor from experiencing any subsequent damage. They are a reliable cost-effective option. Both IEC relays and NEMA relays can be configured with a thermal overload mechanism.
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